Color photography



. 5 illllaims.

Uur present invention relates to color photography and more particularly to a process and material in which color is produced in a colloidal emulsion layer by the action of an oxidation product of a photographic developer on a dyestuff component'incorporatedinsaid layer! This process of color forming development has first been disclosed in U. S. Patents 1,102,028 and i,055,155 to Fischer.

If a photographic emulsion layer containing these dyestuff components is developed by means of a developer containing free amino groups, for instance phenylene-diamines, especially the monoor unsymmetrically disubstituted ones like p-dimethylaminoaniline, ethoxy-p-dimethylaminoaniline, there is obtained a colored photographic picture.

The color of the pictures depends upon the I dyestufi forming components applied to the layer. Pyrazolones for instance yield blue-red dyes, de-

rivatives of acetoacetic ester yield yellow colorings, and naphthols yield blue colors.

The dyestuff components of Fischer, however, merely lent themselves to the production of pictures in one single color., When dyestufi' components which yield various colors by development were incorporated in several superposed layers it became apparent after developing that the components had diffused into all the other layers, viz., that a separation of the color values of the photographed object had not been achieved. Even if components were selected from those listed in the aforementioned patents which are dimcultly soluble, i. e., which are capable of being incorporated in the layers in the form of an insoluble precipitate, these components did not show a satisfactory fastness to diflusion, unless they were entirely insoluble, in which case they did not react at all with the developers and merely a black silver picture was produced.

Even for the production of single-colored reversal pictures the dyestuff components were useless inasmuch as they were washed out of the layers during the black-and-white development, so that for the subsequent color development an insufficient amount of them remained in the layers, or at least they were apt to diffuse into the developer itself thereby soiling pictures which were simultaneously developed in another color. It is therefore an object of the present invention to provide a material in which all these disadvantages and drawbacks are overcome.-

A further object is to'provide a process by which dyestufi components may be obtained which are soluble in aqueous liquids and which @DLOB. PHOTOGRAP Gustav Wilmanns, Wolfen, Kreis Eitterfeld, Wilhelm Schneider, Dessau, and Ernst Bauer, Hersbruck, Min, Germany, assignors, by mesme assignments, to .dgfa Ansco Corporation, hinghamton, N. Y a corporation oi Welaware No brawing. Application November 13, 193i, Se-

rial No. W435i). in Germany April lit, 1935 for instance dik'etohydrindene; pyrazolones are fast to diffusion once theyareincorpora d in the photographic emulsion layers.

A further object is to provide dyestuff cjo nents which will not be removed fronftheir spective photographic layers by the 'aeti aqueous alkaline liquids such as'for insta veloping solutions. a COlOr photographic multi-layer material prising a series of superposed emulsionf each layer containing a dyestuficompon the above described kind. 1

Further objects will be apparentfroint tailed specification following hereafter.

This application is to be jregarded as 'a tinuation in part of our'cop'ending applicatf 1 Ser. No. 72,718 filed April 4, i936. x

The invention is based on the ob'servatio th by adding groups to the coupling compo having so large a number of atoms that the e their solubility in aqueous'liquids, do not to diffuse from the photographicemulsio or into the developing solution. i i As dyestufi components which maybes tuted by radicals which will increase'their ular size the following may be' namedby example: All compounds with an active methylene grou for instance acetoacetic ester, bromacetoac ester, acetoacetic anilide, cyanoacetic ester, b

zoylacetoacetic ester, benzoylacetic acid and terephthaloylacetic ester, 'hydrindenes such as for instance 1-phenyl-ii methyl pyrazol l phenyl-B -phenyl-pyrazolone, couniar'an malonic acid anilide-,omega-cyanoacetopheiioh hydroxythionaphthene etc. lhere are further used phenols such as for example meta-arn'n phenol, o-o'-dinaphthol, o-hydroirydiphenyl dihydroxydiphenyl, substituted naphthols instance e-naphthol, dinaphthol, 1,5-hydrdx naphthol, chloronaphthol and trichloronaphth substituted aminonaphthols, for instance aminonaphthol, phenolcarboxylic acids, tor stance salicylic acid, naphthol' carb'dxylicaci for instance a-hydroxynaphthoic acid. Oil-t benzene and naphthalene derivativestho se droxy compounds are especiallysuitablewh in p-position to the hydroxy grous aveanejr n t substituent at all or a negativesubstituents as for instance chlorine, sulfonidacid. other substitution products of the above harried. 55

compounds may "be used, such as for instance nitro derivatives.

It is impossible to define a general chemical structure of the radicals which are to be introduced into the molecule of the aforementioned coupling components. However, it should be generally stated that all organic radicals which produce a substantial increase in the molecular size of the dyestuif components are suitable for the purpose of the present invention. The exact size of the radicals which-are to be introduced depends largehr upon the tendency of diifusion which the substituted dyestuif component possesses. .Thus radicals from 5 carbon atoms upwards will be very useful in some cases, while in others radicals of at least 12 to 18 carbon atoms are required.

The carbon atoms may be arranged in chain or nuclear formation and they may be linked to 20 hydrogen or other atoms, such as oxygen, sulfur, selenium, nitrogen and halogen etc. These radicals may in themselves have the structure of the aforementioned dyestufi components so that dyestufl components which are obtained by linkage of several molecules of coupling components are also within the scope of the present invention.

For the synthesis of these compounds it is advisable to introduce the radicalswhich impart the fastness to diffusion to the molecule of the dyestufi forming component by means of an amino, carboxyl, or hydroxyl group in the form of an amide or an ester. However, a direct connection by means of C-C-linkage of coupling component and the radical to be introduced is also possible. Also Schifis bases may be formed. In order to increase the solubility of the compounds they may contain special groups imparting solubility to them as for instance carboxyl or sulfo-groups.

For the production of photographic layers, especially those dyestufi components will be suited which may be introduced into the layer in a dissolved state. It has been found that in the manner suggested above components may be obtained which possess a satisfactory fastness to diffusion in dilute alkaline solutions and which are soluble in aqueous liquids in some cases by addition of slight quantities of an organic solvent, so as to be easily incorporated in photographic layers in a dissolved state. Of course there always exists the possibility of introducing the undissolved dyestuff components into the layer, but such layers yield less clear pictures and pictures of coarser grain.

Of the great number of groups which come into question for the production of dyestufi components fast to difiusion some have been found to be especially suitable. Such groups are for instance the substantive groups with which direct cotton dyestuffs of good qualities of fastness could be obtained. Chemically these are groups which contain a comparatively long chain of conjugated double bonds, such as for instance diphenyl, dianisidine, tolidine, diphenyl-carboxylic acid, 3-hydroxy-4-diphenyl-carboxylic acid, diaminobenzoylaminodiphenyl, 2,2'-dihydroxy-4,4-diaminodiphenyl, stilbene, diaminostilbene, diaminobenzoylaminostilbene, azoxybenzene, hydroxynaphthoic acid, for instance 2,3-hydroxynaphthoic acid, 4,2',3'-hydroxynaphthoylaminoaniline, diaryl ureas, as for instance diaminodiphenylurea, diaminobenzoylaminodiphenylurea, the carbamide of aminobenzoylamino-o-sulfanilic acid, heterocyclic nuclei as for example triazines, thiazoles, benzthiazoles, dehydrothiotoluldines, oxazoles, nuclear cyanuric derivatives in which several dyestuif components are linked by means of the cyanuric nucleus and which may contain still further substantive groups, furthermore certain aminonaphthols as for instance 2-amino-5-naphthol-7-sulfonic acid and 2-aminobenzoylamino-5-naphthol-sulfonic acid, furthermore highly molecular compounds as terephthaloylbisacetic ester, 2,3-hydroxyanthracene carboxylic acid, 2,3-hydroxycarbazo1e carboxylic acid, aminochrysene, aminopyrene, aminonaphthyleneoxide.

The compounds obtained in this manner may be dissolved in alkali with perhaps an addition of alcohol or other organic solvents and may then be added to layer forming colloids without any precipitation. The fastness to diffusion of these components may further be increased by the introduction into their molecule of still fur- 8 grams of the resulting compound are dissolved in 3 cc. of sodium hydroxide of 40 per cent strength, 25 cc. of methanol, and 70 cc. of water and then added to 500 cc. of a gelatin emulsion of 5 per cent strength. By developing with p-di ethylaminoaniline a blue picture is obtained.

2. From salicyclic acid chloride and benzidine a dyestufi component of the following formula is obtained:

on on There are added to the component 9 grams of salicyclic acid chloride dissolved in the same manner as in Example 1 and 500 cc. of a 5 per cent emulsion. By developing with p-diethylaminoaniline a blue picture is obtained.

3. From dehydrothiotoluidine and a-hydrownaphthoic acid chloride the following component is obtained:

5 grams of this compound are dissolved as described in Example 1 and added to a 5 per cent gelatin emulsion. By developing with a color forming developer 2. blue picture is obtained.

4. From dehydrothiotoluidine and salicylic airmen acid chloride the following compound, which yields a blue icture. is obtained 5. A component yielding a blue picture and having the formula:

a ma HaC may be obtained from l-p aminophenyl -limethyloxazole and hydroxynaphtholc acid chloride.

6. A component yielding a red picture and having the formula:

S ONH-O 0 i0- l I N/ ll l is obtained from the hydrazine of the dehydro thiotoluidlne which is condensed with p-nitrobenzoylacetic ester, then reduced and again condensed with benzoylchloride. The compound is dissolved as described in Example 1.

l. A dyestuii component yielding a red picture and having the formula:

is obtained by heating 2 mols of benzoylacetlc ester and 1 mol of benzidine. 3 grams of the compound are dissolved according to the prescriptions given in Example 1 and added to 500 cc. of a 5 per cent gelatin emulsion.

10. A compound of the formula yields when developed with color forming developers a yellow picture. The compound is obtained by heating 2 mols of benzoyl-acetic ester and di-p-aminophenylurea in boiling zylene while at the same time distilling off the formed alcohol.

ii. A compound of the formula OH OH (ilH HJO- \vQN/ I N/ vi 0 Ha is'obtained in analogous manner as in the preceding example with the sole exception that the last process step consists in condensing with diphenylcarboxylic acid chloride instead of with benzoylchloride.

8. A dyestufi component yielding a red picture and having the formula:

is obtained from the hydrazine of the 2-p-amino- S-methylbenzoxazole which is condensed with pnitrobenzoylacetic ester, whereat the nitro group is reduced to the amino group and the latter reacted with diphenyl-dicarboxylic acid chloride.

9. A dyestuif component yielding a yellow picture and having the formula:

component having linked to an atom of its molecule the diphenyl grouping, said grouping being capable of rendering said component fast to diffusion.

3. A photographic emulsion layer having incorporated therein a color forming development component having linked to an atom of its molecule the stilbene grouping, said grouping being capable of rendering said component fast to diffusion.

i. A. photographic emulsion layer having incorporated therein a color forming development component having linked to an atom of its molecule the benzthiazole grouping, said grouping being capable of rendering said component fast to diffusion.

5. A photographic silver halide-gelatine emulsion layer having incorporated therein a color forming development component having linked to an atom of its molecule a group of so large a diflusing in gelatine in any photographic treating number of atoms that the molecular size of said bath.

component is more than doubled, said compo- GUSTAV WILMANNS. nent although soluble in aqueous photographic WILHELM SCHNEIDER. developing solutions being as a result of its mo- ERNST BAUER.

lecular size incapable in such dissolved form 01 

